This is a revised new Program Project application from an interactive group of experienced investigators consisting of 3 projects and 3 cores. The overall theme of this PPG is to understand how arterioles are regulated by interactions between cell integrins and extracellular matrix (ECM) proteins and how these interactions are disturbed by vascular disease. Over the last 12 years, program investigators published most of the early work establishing a key role for integrins in microvascular control. Recent insights by our investigative team have identified key integrins and ECM proteins setting the stage for major breakthroughs in this field that will significantly advance our understanding of this paradigm for microvascular control. A central premise of this PPG is that microvascular control in health and disease is influenced by properties of the ECM and ECM interactions with integrins on cells of the microvascular wall. Project 1 will examine the ability of vasoactive mediators to influence integrin-ECM adhesion and determine how adhesion is coordinated with microvascular smooth muscle cell (mVSMC) contraction and control of arteriole diameter. Project 2 will examine the ability of ECM proteins to signal through integrins and modulate Mvsmc membrane conductance of Ca2+ and K+ to control vasomotor tone. Project 3 examines a unique hypothesis that during inflammation emigrating leukocytes cause ECM degradation that generates integrin-binding signals that impair control of arterioles. Core A will provide administrative support for the PPG. For all projects, Cores B will provide imaging technology/support and Core C will provide for molecular and cell level technologies. Together, the projects will shape an integrated view of microvascular regulation using model systems that include freshly isolated mVSMC, isolated arterioles and microvascular network preparations. A multidisciplinary array of technical approaches ranging from atomic force microscopy, fluorescence microscopy, electrophysiology and molecular techniques will allow a comprehensive and systematic exploration of concepts. (End of Abstract)